21266273 has 4 divisors (see below), whose sum is σ = 24304320. Its totient is φ = 18228228.

The previous prime is 21266239. The next prime is 21266291. The reversal of 21266273 is 37266212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21266273 - 2⁸ = 21266017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21266213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1519013 + ... + 1519026.

It is an arithmetic number, because the mean of its divisors is an integer number (6076080).

Almost surely, 2^21266273 is an apocalyptic number.

It is an amenable number.

21266273 is a deficient number, since it is larger than the sum of its proper divisors (3038047).

21266273 is an equidigital number, since it uses as much as digits as its factorization.

21266273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3038046.

The product of its digits is 6048, while the sum is 29.

The square root of 21266273 is about 4611.5369455313. The cubic root of 21266273 is about 277.0535982161.

The spelling of 21266273 in words is "twenty-one million, two hundred sixty-six thousand, two hundred seventy-three".